New puerulus collector design suitable for fishery-dependent settlement monitoring

Abstract

Abstract Fishery-independent diver-based puerulus settlement monitoring has been conducted for over two decades in sheltered inshore shallow sites on the Tasmanian coast and has been utilized in the development of a predictive capacity for the Tasmanian lobster fishery. However, the majority of catches in this fishery are sourced from deep (>50 m), remote, and highly exposed areas where it is impractical and expensive to conduct fishery-independent routine settlement monitoring. To determine if pueruli settle in deeper waters, we adapted a crevice puerulus collector to fit within a lobster trap frame specifically designed to be deployed and serviced by vessels typical of the Tasmanian lobster fleet. A 5-month trial yielded puerulus catches similar to those from inshore shallow sites including recording puerulus from waters more than 100 m depth. The collector design was reported by fishers to be safe and convenient to service in regions exposed to strong westerly winds and swell more than 7 m. This collector will allow a cost-effective fishery-dependent approach to puerulus settlement monitoring utilizing commercial fishers for field operations and researchers for administration, sorting, and analysis.